The present invention refers to an apparatus for dispensing a controlled dose of a liquid fluid, such as a liquid pharmaceutical, and in particular to a dispensing apparatus for nasal administering of such a pharmaceutical.
Pharmaceutical agents are commonly administered in substances which contain a unit dose of the respective agents. Those agents which should be injected are usually commercialized in form of ampoules which contain the dose to be administered. For hygienic reasons, such form of dosages is desirable because a repeated withdrawal from a larger supply of pharmaceutical and subsequent metering in single doses is avoided. On the other hand, when liquid pharmaceuticals are concerned which are directly administered to the patient, the commercialization of such single doses is troublesome because they usually require a simultaneous supply of expensive dispensing devices which render the distribution of numerous pharmaceuticals in single doses practically impossible.
This is especially true for the nasal application of liquid pharmaceuticals which are administered by evenly spraying a pharmaceutical via a spray head in each nostril of the nose. Spray devices are relative expensive and thus are designed for multiple application which is, however, undesired when administering pharmaceuticals which for diagnostic purposes should be delivered into the nostrils only once. Although it would be possible to exchange the spray heads or to use respective tops; in case a medication is concerned which is rarely used in a professional office, there is still the drawback that a physician has to store a large supply of such a medication even when only sparingly using it. Such a case is conceivable for example, for diagnostics of thyroid diseases during administering of thyrotropin-releasing-hormone as single dose to a patient for determining thyroid conditions based on the increase of the serum level of thyrotropin.
For various reasons such as compatibility, the nasal application of a test dose is especially desirable. Since, however, the test dose should be administered only once and evenly in both nostrils, the spraying devices used for such purposes proved to be too complicated and too expensive so that the price of such medications or pharmaceuticals increased significantly.